Are you looking to shoot them or hunt with them? I can propose a number of solutions.
Many Mosin Nagants (7.62x54r) have longer barrels, The cartridge is easy on the shoulder and there is no muzzle blast.
I have a number of single shots with longer barrels. They are range rifles, but I suppose they could go hunting as well. I have a 303 British (a 30-303 actually) that is 26 inches long on an Encore action. A few P14s with 26 inch barrels as well.
You can have a longer barrel screwed onto an action of your choice as well. That's more expensive, but an option. 26 inches should do it.
You shoot different Mosin Nagants than I do. And I've had 6 of them
